{
  "format_version": "1.13.0",
  //The schema is exactly right; floats can be used for volume, but they're truncated as always, so indeed integers are the recommended type.
  "minecraft:search_feature": {
    "description": {
      "identifier": "search_features:search_feature"
    },
    "places_feature": "search_features:search_feature_obsidian",
    "search_volume": {
      "min": [0, 30, 15],
      "max": [0, 100, 15]
    },
    "search_axis": "-y",
    "required_successes": 3
  }
}